Research Project
Grant-in-Aid for Scientific Research (C)
The purpose of this study was to assess the effects of pioglitazone on arrhythmogenic atrial structural remodeling versus the effects of the angiotensin II type 1 receptor blocker candesartan in a rabbit model of congestive heart failure.Rabbits subjected to ventricular tachypacing at 380 to 400 bpm for 4 weeks in the absence and presence of treatment with pioglitazone, candesartan, and combined pioglitazone and candesartan were assessed by electrophysiologic study, atrial fibrosis measurements, and cytokine expression analyses.Atrial fibrillation(AF) lasting longer than 2 seconds was induced in no nonpaced controls but in all ventricular tachypacing-only rabbits(mean duration of AF : 8.0 ± 1.4 seconds). Pioglitazone reduced the duration of AF(33 ± 0.2 seconds, P <.05)and attenuated atrial structural remodeling, with significant reductions in interatrial activation time (50 ± 2 ms vs 41 ± 2 ms, P <.05) and atrial fibrosis(16.8% ± 0.8% vs 10.9% ± 0.7%, P <.05 ; control 1.6% ± 0.2%), effects comparable to those of candesartan(duration of AF : 3.0 ± 0.2 seconds ; activation time 44 ± 2 ms ; fibrosis : 9.4% ± 0.6%). Both pioglitazone and candesartan reduced transforming growth factor-al, tumor necrosis factor-o, and activated extracellular signal-regulated kinase expression similarly, but neither affected p38-kinase or c-Jun N-terminal kinase activation. The effects of combined pioglitazone and candesartan therapy were not significantly different from the effects of pioglitazone or candesartan alone.Pioglitazone can attenuate congestive heart failure-induced atrial structural remodeling and AF promotion, with effects similar to those of candesartan. PPAR u may be a potential therapeutic target for human AF.
All 2008 2007 2006
All Journal Article (25 results) (of which Peer Reviewed: 14 results) Presentation (3 results)
Heart Rhythm 5
Pages: 451-459
Circ J 72
Pages: 281-286
Heart Rhythm 5(3)
Circ J 72(2)
Pages: 28128-6
110006571057
Pacing Clin Electrophysiol 30
Pages: 1323-1330
Heart Rhythm. 4
Pages: 1284-1291
J Am Coll Cardiol 50
Pages: 884-891
Europace 10
Pages: 869-874
J Electrocardiol 40
Pages: 319-325
J Am Coll Cardiol 49
Pages: 1436-1442
Pacing Clin Electrophysiol 30(11)
Heart Rhythm 4(10)
J Am Coll Cardiol 50(9)
Europace 9(10)
J Electrocardiol 40(4)
J Am Coll Cardiol 49(13)
Circ J 70
Pages: 1385-1391
Pacing Clin Electrophysiol 29
Pages: 1069-1074
Pages: 1180-1183
Circ J 70(11)
110004858624
Pacing Clin Electrophysiol 29(10)
Circ J 70(9)
110004814895